This invention relates to certain carbostyril compounds and to pharmaceutically acceptable salts thereof which are useful as cardiotonic agents, processes for preparing the same, and pharmaceutical compositions containing the carbostyril compounds or salts thereof.
Various carbostyril compounds are known which have cardiotonic activity as described in U.S. Pat. No. 4,415,572.
However, the carbostyril compounds of this invention are structurally different from the conventional carbostyril compounds.